Integral type flat antenna provided with converter function

An integral type flat antenna provided with a converter function comprising:

• an antenna element having a feeding point;
• and
• an integrally formed multilayered substrate for supporting said antenna element thereon, said multilayered substrate comprising:
• a grounding plane layer for providing earth of said antenna element;
• a first insulating layer provided below said grounding plane layer;
• a second insulating layer provided having an end portion, said second insulating layer being positioned below said first insulating layer and provided with a frequency conversion circuit for carrying out a converter function on frequency of received signals, and said frequency conversion circuit having a signal input which is positioned at the end portion of said second insulating layer;
• a third layer provided between said first and second layers;
• and
• a flat plate-shaped conducting layer positioned between said first and third insulating layers for electrically connecting said feeding point of said antenna element to the signal input of said frequency conversion circuit.